Apparatus and method for image and print blanket enhancement

Abstract

Apparatus and methods for improving print quality and print blanket life in liquid electrostatic printing, for example, forming a first toner image on an image surface; first transferring the first image to an intermediate transfer member; then transferring of the first image from the intermediate transfer member to a final substrate; affixing the first image on the final substrate; rotating the first image to create a second image; and, repeating the method using the second image.

1. A method of electrostatic printing, comprising:
 forming a series of toner images on an image surface; 
 serially transferring said images to an intermediate transfer member, ITM; 
 then transferring said images from said intermediate transfer member to a series of substrates or to different positions on a web substrate; 
 wherein at least some of said images are transferred to said ITM in different positions or orientations on said ITM by utilizing partial null cycles. 
 
     
     
       2. A method according to  claim 1 ,
 wherein at least some of the images are rotated compared to other images in the series. 
 
     
     
       3. A method according to  claim 2 , wherein said rotation is 180°. 
     
     
       4. A method according to  claim 2 , further comprising selectively rotating the substrate after printing thereon to provide a common orientation to the series of printed images. 
     
     
       5. A method according to  claim 1  wherein the series of substrates are a series of sheets and wherein the images are transferred to the sheets in a same position on said sheets, even when the images are in different positions on the ITM. 
     
     
       6. A method according to  claim 1 , wherein said transferring images to said ITM in different positions or orientations is performed at a predetermined frequency. 
     
     
       7. A method according to  claim 1  wherein the toner comprises a carrier liquid that is absorbed by a surface of the ITM. 
     
     
       8. A method according to  claim 7  wherein amount of carrier liquid absorbed by the intermediate transfer member is different for image and background areas of the image. 
     
     
       9. A method of electrostatic printing, comprising:
 forming a series of toner images on an image surface; 
 serially transferring each said image after formation to an intermediate transfer member, ITM; and 
 transferring each said image from said intermediate transfer member to a substrate; 
 wherein at least some of said images are transferred to said ITM in different positions, said different positions being such that at least one of the images partially, but not completely, overlaps a previous image on said ITM. 
 
     
     
       10. A method according to  claim 9  wherein the substrate is a web. 
     
     
       11. A method according to  claim 10  wherein the web is advanced or retarded prior to transfer of an image thereto to compensate for displacement of the image on the ITM. 
     
     
       12. A method according to  claim 9  wherein the images in different positions on the ITM are displaced in a process direction on the ITM. 
     
     
       13. A method according to  claim 9  wherein the substrate comprises a series of substrates positioned relative to the ITM at different index positions to compensate for displacement of the images on the ITM. 
     
     
       14. A method according to  claim 9  wherein the images in different positions on the ITM are displaced in a direction lateral from a process direction on the ITM. 
     
     
       15. A method according to  claim 14  wherein the substrate is displaced laterally prior to transfer of an image thereto to compensate for displacement of the image on the ITM. 
     
     
       16. A method according to  claim 15  wherein the substrate is aligned with other substrates bearing other images in said series after printing. 
     
     
       17. A method of electrostatic printing, comprising:
 forming a series of toner images on an image surface; 
 serially transferring each said image after formation to an intermediate transfer member, ITM, wherein different images are transferred to different positions on the ITM; 
 transferring each said image from said intermediate transfer member to a substrate; 
 wherein the images in different positions on the ITM are displaced in a direction lateral from a process direction on the ITM, wherein the substrate comprises a web that is displaced laterally prior to transfer of an image thereto to compensate for displacement of the image on the ITM. 
 
     
     
       18. Printing apparatus comprising:
 a printing engine that receives data from a data source, the printing engine comprising;
 a first surface adapted to hold toner images; 
 an intermediate transfer member that receives toner images from the first surface, 
 
 a sheet or web substrate feed that feeds a substrate to the printing engine such that toner images are transferred to the substrate from the intermediate transfer member; and 
 a controller operative to rotate or shift a position of toner images in a series of images such that the toner images are transferred to the intermediate transfer member at different positions, said different positions being such that at least one of the toner images partially, but not completely, overlaps a previous toner image on said intermediate transfer member.